The Neuropathology (NP) Core of this ADCC will provide for post-mortem diagnoses on patients and control subjects enrolled in the clinical core and on other well-documented AD cases and controls. The protocols used by the NP aim to be state of the art and consistent with 21st century brain banking procedures, which is essential to met the increasingly sophisticated needs of the AD research community {3922, 3921, 3920, 3919, 3918}. The tissue of the NP core is banked and distributed for research purposes as determined by the Tissue Utilization Committee, while protecting the privacy of research subjects. Part of this NP core and unchanged from the prior grant period, is a Morphometric Component performed at the Institute for Basic Research (IBR) on Staten Island. The Morphometric Component of this core is essential for the careful characterization of AD and control brain tissue in terms of the volume of different brain structures, number of neurons, glial cells, amyloid load and neurons with neurofibrillary change. This information can then be used for precise clinico-pathological correlation. The Specific Aims of this Neuropathology Core are: 1 .To conduct thorough postmortem examinations on NYU ADCC patients (N=25-30/yr from NYU) using the NIA-Reagan Institute Working Group criteria for the diagnosis of AD. 2.To maintain a bank of unfixed frozen and fixed tissue from the ADCC control and patients with AD or other dementing neurodegenerative conditions. 3.To provide tissue from control brains, AD and other neurodegenerative conditions to AD and prion researchers within and outside this ADCC in order to augment clinical and basic research on dementia. 4.To conduct morphometric studies on AD to establish better clinical neuropathological correlation, in particular to document the progression of the earlier stages of AD pathology. 5.To conduct anatomic and pathologic correlation with in vivo and post mortem MR scans in collaboration with the Neuroimaging Core. 6.To collaborate in the research efforts of the other cores and projects of the ADCC, as well as providing advice and facilities to investigators within and outside the ADCC who seek to conduct morphometric, immunohistochemical of demented and control patients using post-mortem tissue.